Method op forming a rectangular heat duct

ABSTRACT

A MACHINE DESIGNED TO CONTINUOUSLY PROGRESS A PAIR OF ELONGATED FLAT SHEETS OF METAL LONGITUDINALLY THROUGH A PLURALITY OF COOPERATIVE DIES WHICH PROGRESSIVELY IN SEQUENTIAL STEPS GRADUALLY SHAPE THE TWO SHEETS INTO A DUCT HAVING A RECTANGULAR CROSS-SECTIONAL CONFIGURATION. THE MACHINE UTILIZES COOPERATIVE ROTARY DIES TO SHAPE AND FORM THE DUCT IN A CONTINUOUS OPERATION TO A LENGTH EQUAL TO THAT OF THE SHEETS SO THAT RECTANGULAR DUCTS OF ANY DESIRED LENGTH CAN BE PRODUCED IN AN AUTOMATIC OPERATION BY MERELY INSERTING INTO THE MACHINE A PRE-PREPARED ROLL COMPRISED OF A PAIR OF SHEETS OF METAL OF THE DESIRED LENGTH, THE SHEETS ENTERING THE MACHINE AT ONE END AND   LEAVING THE SAME AT THE OTHER END IN THE FORM OF A CONTINUOUS RECTANGULAR DUCT.

1974 L. E. ANDERSON ETAL Re. 28,088

METHOD OF FORMING A RECTANGULAR HEAT DUCT l0 Sheets-Sheet 1 OriginalFiled Feb. 19, 1970 y 1974 L. E. ANDERSON ETAL Re. 28,088

IETHOD OF FORMING A RECTANGULAR HEAT DUCT Original Filed Feb. 19, 1970l0 Sheets-Sheet l Fla. 3

5/ 650440.! Mu/v/v July 30, 1974 L. E. ANDERSON ETAL Re. 28,088

IETKOD 0F FORMING A RECTANGULAR HEAT DUCT Original Filed Fob. 19, 197010 Sheets-Sheet 5 75 F/qa I N VENTURE zikarflA/ mson BY GzmwJMww July30, 1974 E soN ETAL Re. 28,088

. IBTHOD OF FORMING A RECTANGULAR HEAT DUCT Original Filed Feb. 19, 197010' SheetsSheat 4 1 590 y Eflzvoszsoxv By GER/91.0.1 Mumv jwmiwwm July30, 1974 L. E. ANDERSON ETAL Re. 28,088

IETHOD OF FORMING A RECTANGULAR HEAT DUCT l0 Sheets-Sheet 5 OriginalFiled Feb. 19, 1970 INVENTORS zmorfifl/voaksofl y GERALDJ Mu/wv MWJW'July 30, 1974 1.. E. ANDERSON EI'AL Re. 28,088

IETHOD OF FORMING A RECTANGULAR HEAT DUCT Original Filed Feb. 19, 197010 Sheets-Sheet 6 BY a'mnuu MuNN Arrows r:

y 1974 L. E. ANDERSON EI'AL Re. 28,088

IETHOD 0F FORMING A RECTANGULAR HEAT DUCT l0 Sheets-Sheet 7 OriginalFiled Feb. 19, 1970 y 30, 1974 E. ANDERSON ETAL Re. 28,088

HETHQD OF FORMING A RECTANGULAR HEAT DUCT Original Filed Feb. 19, 197010 Sheets-Sheet B 4 w b 6 5 fl 7;

0 Z 5 i w m 4 Z 6 m m H W 0 2% M m 7 z 9 E w m 1 5; 7 TH. k F

INVILV/ORS 5207 ffllmikson BY GEAHLDJ Mun/v I 147T0RNEX3' July 30, 1974L. E. ANDERSON ET AL IETBOD OF FORMING A RECTANGULAR HEAT DUCT OriginalFiled Feb. 19, 1970 10 Sheets-Sheet a IN VEN TORS Z ERG/15 flNDf/RSON BY65mm J. Mu/v/v ,z MMMJM United States Patent 28,088 METHOD OF FORMING ARECTANGULAR HEAT DUCT Leroy E. Anderson and Gerald J. Munn, DetroitLakes,

Minn., assignors to Manufacturers Systems, Inc., Detroit Lakes, Minn.

Original No. 3,722,443, dated Mar. 27, 1973, Ser. No. 205,843, Dec. 8,1971, which is a division of application Ser. No. 12,663, Feb. 19, 1970,now Patent No. 3,636,- 903. Application for reissue June 6, 1973, Ser.No.

Int. Cl. B21d 39/02 US. Cl. 113-54 34 Claims Matter enclosed in heavybrackets appears in the original patent but forms no part of thisreissue specification; matter printed in italics indicates the additionsmade by reissue.

ABSTRACT OF THE DISCLOSURE A machine designed to continuously progress apair of elongated fiat sheets of metal longitudinally through aplurality of cooperative dies which progressively in sequential stepsgradually shape the two sheets into a duct having a rectangularcross-sectional configuration. The machine utilizes cooperative rotarydies to shape and form the duct in a continuous operation to a lengthequal to that of the sheets so that rectangular ducts of any desiredlength can be produced in an automatic operation by merely insertinginto the machine a pre-prepared roll comprised of a pair of sheets ofmetal of the desired length, the sheets entering the machine at one endand leaving the same at the other end in the form of a continuousrectangular duct.

This invention relates to heating ducts. More particularly, it relatesto machines for forming elongated metal ducts having a rectangularcross-sectional configuration. This application is a divisionalapplication of our copending application, Ser. No. 12,663, filed Feb.19, 1970, and entitled Rectangular-Duct Forming Machine, now US. Pat.No. 3,636,903.

There is a vast demand today for elongated metal ducts which aregenerally rectangular in cross-sectional configuration. Thisparticularly true in the heating industry and especially true withrespect to the manufacture of mobile homes. The manufacture ofrectangular heating ducts has posed a substantial problem for a longtime, particularly where the duct is to be quite extensive in length, aswill be realized from the description hereinafter of the method by meansof which such ducts have been formed.

The conventional manner of producing rectangular heating ducts hasheretofore involved first the selection of a flat sheet of metal of thedesired length of the heating duct, provided such length was not toogreat to make proper handling of the sheet possible. Where relativelylong lengths of heating duct were required, such ducts were made inshorter sections and then subsequently secured together. This wasparticularly true where the ducts had to be transported from thelocation of manufacture to the location of installation. To manufacturethe heating ducts, the flat sheet was formed with a male lock at oneedge and a female lock at the opposite side edge, and thereafter theelongated sheet was bent simultaneously throughout its length to impartthe rectangular shape and to bring the male and female edges together,preparatory to moving them into mating relation. The final step involvedthe insertion of the male into the female lock to lock the same to eachother. Great difficulty has been experienced in assembling these locks,the main problem being the fact that the male or female edge isfrequently ice bent inadvertently during the efforts involved in shapingthe flatsheet into the desired rectangular shape, and, as a consequence,great difliculty is experienced in bringing the two edges into propermating relation. The length of such sections is obviously limitedbecause of these difficulties. Since a duct of any appreciable lengthmust be assembled section by section if it is to be manufactured by themethods heretofore known, a great expenditure of time, effort, andmaterials is involved in the manufacture of ducts having appreciablelength by these methods.

It is a gneral object of our invention to provide a machine constructedand arranged to continuously form an elongated duct having a rectangularcross-sectional configuration from a pair of fiat sheets of metal fedinto the machine simultaneously.

A more specific object is to provide a machine constructed and arrangedto continuously progress a pair of elongated sheets of fiat metalthrough the machine and automatically form therefrom, in continuousprogression, a duct having a rectangular cross-sectional configuration.

A more specific object is to provide a novel machine having a pluralityof cooperating rotary dies mounted in spaced relation along the lengthof a supporting frame and adapted to receive and progressively shapealong their length a pair of elongated flat sheets of metal, insequential steps, into a duct having a rectangular cross-sectionalconfiguration.

Another object is to provide a machine constructed and arranged toreceive and continuously progress a pair of elongated fiat sheets ofmetal therethrough, the sheets being formed by and leaving the machinecontinuously in the form of a duct having a rectangular cross-sectionalconfiguration, the forming of the duct being accomplished through aseries of partial progressive bending steps accomplished sequentiallythrough the use of rotary dies at points spaced along the length of thesheets while they are passing through the machine.

Another object is to provide a novel machine constructed and arranged toenable a duct manufacturer to rapidly and efficiently produce elongatedducts of rectangular cross-sectional configuration of any predeterminedlength by merely feeding into the machine a pair of fiat sheets of metalpre-cut to the same predetermined length.

Another object is to provide a novel machine constructed and arranged tomanufacture rectangular ducts of any predetermined length at a verysubstantial saving in time, labor and costs.

Another object is to provide a novel machine constructed and arranged tomanufacture rectangular ducts automatically at great saving, the machineitself being compact, automatic in operation, inexpensive tomanufacture, trouble-free in operation, and inexpensive and simple tooperate and maintain.

Another object is to provide a portable machine which permits users ofrectangular ducts such as mobile home manufacturers to manufacture theirducts needs in single sections of desired length, whatever they may be,at their Operations base, to thereby eliminate the need for transporting preformed tubular sections thereto.

Another object is to provide a novel machine which constructsrectangular tubular ducts from pairs of fiat sheets of metal in anautomatic operation which produces an end product having improvedquality and performance characteristics.

Another object is to provide a machine which automatically constructsrectangular ducts from pairs of fiat sheets of metal and which obviatesthe heretofore need of forming such ducts by bending the material fromwhich the duct is to be made simultaneously throughout its length andwhich obviates the great difficulties heretofore encountered inassembling the male and female locks utilized in the known conventionalmanufacturing methods of ducts so shaped.

These and other objects and advantageous of our invention will morefully appear from the following descrip tion, made in connection withthe accompanying drawings, wherein like reference characters refer tothe same or similar parts throughout the several views, and in which:

FIG. 1 is a diagrammatic plan view of the preferred form of ourinvention with stations indicated thereon and without the seamflattening mechanism being included;

FIG. 2 is a diagrammatic side elevational view of the embodiment shownin FIG. 1;

FIG. 3 is a diagrammatic vertical sectional view taken through stationNo. l of the embodiment shown in FIG. 1;

FIG. 4 is a diagrammatic vertical sectional view taken through theembodiment shown in FIG. I, at station No. 2, and illustrating how theoutermore lateral portions of the two sheets are shaped preliminarilytoward becoming cooperative seam elements;

FIG. 5 is a diagrammatic vertical sectional view taken through theembodiment shown in FIG. 1, at station No. 3, and illustrating themanner in which the innermore lateral portions of the two sheets arecrimped preliminarily to bending each sheet into oppositely facingchannel members and the outermore lateral portions are shaped finallyinto seam elements;

FIG. 6 is a diagrammatic vertical sectional view taken through theembodiment shown in FIG. 1, at station No. 4, and illustrating themanner in which the lateral portions are guided inwardly at the beadline about the fixed die and into the adjacent and following rotary diemembers.

FIG. 7 is a diagrammatic vertical sectional view taken through theembodiment shown in FIG. 1, at station No. 5, and illustrating themanner in which the rotary dies cooperate with the fixed die at the beadline and present the outermore lateral portions of the lower sheettoward the corresponding portions of the upper sheet;

FIG. 8 is a diagrammatic vertical sectional view taken through theembodiment of FIG. 1, at station No. 6, and illustrating the manner inwhich the guide rollers bend the lateral portions of the sheets furtherinwardly about the bead line and present the lower seam elements to theupper seam elements at an inwardly disposed position to facilitatesubsequent inter-engagement;

FIG. 9 is a diagrammatic vertical sectional view taken through theembodiment shown in FIG. 1, at station No. 7, and illustrating themanner in which the cooperative rotary members complete the bend at thebead lines to 90 and commence closing the same;

FIG. 10 is a diagrammatic vertical sectional view of the embodimentshown in FIG. 1, taken at station No. 8, and illustrating thecooperative camming members closing the seam by camming the overlyingseam lip of the upper sheet into parallel and underlying relation to theedge portions of the lower sheet;

FIG. 11 is a diagrammatic vertical sectional view taken through theembodiment shown in FIG. 1, at station No. 9, and illustrating thefinishing operation in which the seam is compressed and buttoned topositively lock the seam elements together;

FIG. 12 is a diagrammatic perspective view illustrating how the two flatsheets are taken from a single roll by the embodiment shown in FIG. 1and progressively formed into a duct having a rectangularcross-sectional configuration, the respective station numbers beingindicated thereon at the point at which the two sheets take the shapesindicated thereat;

FIG. 13 is a diagrammatic side elevational view of the controls for thefeeding mechanism and initial forming rollers at station No. 1;

FIG. 14 is a diagrammatic side elevational view showing the springloading provided for the upper set and lower set of rollers of thefeeding mechanism and initial forming dies of station No. 1;

FIG. 15 is a diagrammatic detailed perspective view of the seam cammingmembers shown in FIG. 10;

FIG. 16 is a detailed diagrammatic view, shown on an enlarged scale, ofthe buttoning operation of the rotary dies shown in FIG. 11;

FIG. 17 is a diagrammatic vertical sectional view of a rectangular-ductforming machine constructed similarly to the embodiment shown in FIGS.1-16, with the exception that its dies are constructed and arranged toform the seams at the corners of the duct rather than at a pointintermediate the corners, the view being taken at station No. 1 with therollers in separated position;

FIG. 18 is a diagrammatic vertical sectional view of the embodimentidentified in the description of FIG. 17 and taken at station No. 2thereof;

FIG. 19 is a diagrammatic vertical sectional view taken at station No. 3of the embodiment identified in the description of FIG. 17 andillustrating the forming of the lip at the extreme lateral portions ofthe wider sheet and the initial break at the innermore lateral portionsthereof;

FIG. 20 is a diagrammatic vertical sectional view taken at station 0. 6of the embodiment identified in the description of FIG. 17 andillustrating the rollers or helpers which guide the roller sheet fromstation No. 3 into the succeeding dies of station No. 5 and initiate thebending of the lateral portions upwardly at the break line incooperation with the fixed die;

FIG. 21 is a diagrammatic vertical sectional view taken at station No. 5of the embodiment identified in the description of FIG. 17 andillustrating the cooperation between the rotary dies and the fixed diesto bend the lateral portions sharply upwardly;

FIG. 22 is a diagrammatic vertical sectional view taken at station No. 6of the embodiment identified in the description of FIG. 17 andillustrating the use of the roller guides to further bend the lateralportions upwardly and inwardly to a point adjacent the lateral portionsof the upper sheet.

FIG. 23 is a diagrammatic vertical sectional view taken at station No. 7of the embodiment identified in the description of FIG. 17 andillustrating the cooperation of rotary dies to form the sealing lip atthe lateral edge of the upper sheet and the bringing of the lateralportions of the lower sheet to a truly vertical position inwardly of thelip;

FIG. 24 is a diagrammatic vertical sectional view taken at station No. 8of the embodiment identified in the description of FIG. 17 andillustrating the cooperation of rotary dies to bring the sealing lip toa vertically extending position at the end of the sealing element of thelower sheet and in position to be sealed;

FIG. 25 is a diagrammatic vertical sectional view taken at station No. 9of the embodiment identified in the description of FIG. 17 andillustrating the cooperation of rotary dies to bring the sealing lip ofthe upper sheet inwardly and around and below the sealing element of thelower sheet;

FIG. 26 is a diagrammatic vertical sectional view taken at station No.10 in the embodiment identified in the description of FIG. 17 andillustrating fixed cams which bring the lip into sealing positionbeneath and against the sealing element at the edge of the lower sheet;

FIG. 27 is a diagrammatic vertical sectional view of the embodimentidentified in the description of FIG. 17 and illustrating the manner inwhich the buttoning dies form the buttons in the seam to lock thesealing elements to each other;

FIG. 28 is a diagrammatic vertical sectional view on an enlarged scaletaken through the channel guides which support the upper metal sheetduring the formation of the embodiment identified in the description ofFIG. 17;

FIG. 29 is a diagrammatic fragmentary side elevational view of a dualcradle mechanism which may be carried by the frame to support twoseparate rolls of sheet metal in feeding relation to either of the ductforming mechanisms in lieu of a single composite roll comprised of apair of such sheets;

FIG. 30 is a diagrammatic vertical sectional view taken through theembodiment of FIG. 1 and showing at station No. structure which may beadded to flatten the seam against the side wall of the duct in the eventsuch is desired;

FIG. 31 is a diagrammatic vertical sectional view taken through stationNo. 11 which may be added to the combined structure shown in FIG. 1 andFIG. 30, illustrating the final step by means of which the seam isflattened against the side wall of the duct.

FIG. 32 is a diagrammatic side elevational view showing the means bywhich the rotary dies illustrated in FIGS. 30 and 31 may be driven bythe same drive mechanisms as that shown in FIG. 2.

The preferred embodiment, as shown in FIGS. 1-16, include a movableframe P which is adapted to be moved to a desired location through theuse of rollers 1 at the lower end of a plurality of vertically extendingsupports 2. A cradle 3 rotatably supports a single roll 4 of a pair 5and 6 of metal sheets. These sheets are arranged in superimposedcontiguous relation with each other and rolled into a single roll sothat their convolutions are concentric. The upper sheet 5 is slightlywider than the lower sheet 6 and, as can be best seen in FIG. 3, theyenter the feeding and initial crimping mechanism, indicated generally bythe numeral 7, in vertically spaced relation as they unwind from theroll 4.

The frame F is elongated and has a pair of vertically extending sidemembers 8 which are transversely spaced from each other and carrysupport brackets 9, which in turn carry elongated transversely spacedfixed inner die members 10. These fixed inner die members 10, as shownin FIGS. 6-9, are comprised of elongated fiat metal plates whichprotrude forwardly beyond the brackets 9 a substantial distance, whichcan be seen by reference tc FIG. 1.

If desired, a pair of separate rolls 11 and 12 (see FIG. 29) of sheetmetal may be utilized in lieu of the single composite roll 4. In thatevent, the rolls 11 and 12 are rotatably supported similarly to the roll4 upon a composite cradle 13, which utilizes saddles 14 and 15 torotatably support the shafts on which the rolls are carried. When dualrolls 11 and 12 are utilized, the upper sheet 15 is fed into the machinein vertically spaced relation to the lower sheet 16, as shown.

FIG. 1 shows the preferred embodiment of our duct forming machine withthe various stations to be hereinafter referred to indicated thereonalong the length of the machine. It will be noted that station No. 1 ispositioned immediately adjacent the roll 4. This station No. 1, which isshown in greater detail in FIG. 3, utilizes a feeding and initialcrimping mechanism 7 which includes an upper set of rotary die members17 and 18, the upper one of which is rotatably mounted so as to becapable of vertical movement relative to the lower rotary die 18. Topermit such movement, each end of the die member 17 is rotatably mountedin a spring loaded bearing structure 19 at each of its ends, the detailsof which are clearly shown in FIG. 14. Thus, the upper roller 17 isconstantly urged downwardly by the action of spring members 20 whichpress the vertically slidable mounting block 21 and the shaft of theroller 17 downwardly toward engagement with the lower die 18, which ismounted for rotation about a fixed axis upon the frame F.

The upper roller 17 has tapered metal end portions 22 and a majorintermediate portion 23, which is formed of a firm but resilientmaterial. The lower metal roller 18 has enlarged end portionscharacterized by a bevelled surface 24, which is complementary to thebevelled surface 22 of the upper roller 17, and a flat angular surface25 which extends parallel to and bears against the cylindrical endportion of the roller 17, so that when the two rollers 17 and 18 arebrought together these surfaces will function as cooperative rotarydies.

The outer surface of the roller 18 is characterized by a plurality ofangular radially outwardly extending circumferential beads 26, which arespaced longitudinally of the roller 18 and a pair of longitudinally andoutwardly extending ribs 27. These ribs 7 extend parallel to the axis ofthe roller 18 and are carried at its circumferential surface and aredisposed at opposite sides of the roller.

The lower set of cooperating rotary dies are adapted to receive andprogress the lower sheet of metal through the machine and they are thecounterpart of the rollers 17 and 18. The lower roller 28 of this set isconstructed similarly to the roller 17 and is similarly mounted forrotation and vertical movement in similar movable bearings, except thatthey are inverted so as to constantly urge the roller 28 upwardly towardthe cooperative rotary die 29 which, like the die 18, is mounted forrotation about a fixed axis on the frame F.

The rotary die 28 has angular beads 30 similar to the beads 26 andlongitudinally extending ribs 31 similar to the ribs 27. It also has abevelled surface 32 similar to the surface 24, but, as shown, it has nosurface comparable to the angular die surface 25. The relatively narrowlower sheet 6 obviates any need for such a surface. The rotary grippingmembers 17 and 28 are adjusted relative to the rotary die members 18 and29 through the use of a control system indicated generally by the letterC, which will be described in greater detail hereinafter.

When the two sheets of metal from the roll 4 have been inserted betweenthe members 17, 18 and 28, 29, they will be progressed thereby throughthe remainder of the machine, since they are each power driven, as willbe hereinafter described. The longitudinal ribs 27 and 31 and theangular beads 26 and 30 impart or form ribs on the surface of the fiatsheets and provide added rigidity thereto. The cooperative bevelledsurfaces 22 and 24 form a 30 Bend of the lateral or edge portions of thesheet 5, and the angular surface 25 shapes the extreme edge portions soas to extend parallel to the main body of the sheet, as will be readilyappreciated by reference to FIG. 3. This is the initial step inprogressively forming the outermore lateral portions of the upper sheetinto a sealing element which will ultimately become a portion of theseam. At the same time, the rotary die 29 imparts a bend to the narrowerlower sheet 6, at its extreme edge, of a 30 angle, there being no edgeportion left extending parallel to the main body of the sheet 6, sincethe sheet is narrower. Thus the extreme edge portion of the sheet 6 isbent downwardly and away from the sheet 5, just as the lateral portionsof the sheet 5 are bent away from the sheet 6.

From station No. l, the two sheets 5 and 6 move to station No. 2, atwhich location it enters the second stage of the duct forming operation.At this location, as shown in FIG. 4, there is positioned a second pairof vertically spaced sets of cooperating rotary dies to impart furthershaping of the lateral portions of the sheets 5 and 6, so that theseaming elements will extend at a 60 angle relative of the main body ofthe sheets. At this station there is located an upper set of rotarydies, identified by the numerals 33 and 34. Each of these dies consistsof a shaft rotatably mounted in the frame F and carrying a rotary diemember at each of its ends and shaped so as to be complementary andcooperate with the die member of the other. Thus the rotary die 33 hasat each of its ends a die member having a fiat annular surface 35 and abevelled 60 surface 26 and an enlarged cylindrical surface 37. The die34 has at each of its ends a rotary die having an annular surface 38 anda 60 bevelled stirface 39 and an enlarged cylindrical surface 40. Asclearly shown in FIG. 4, the surface 35 cooperates with the surface 38and the surface 36 cooperates with the surface 39 to impart a 60 angleto the sealing element, and the surface 37 cooperates with thecylindrical surface 40 to maintain the very edge portion or lip 41parallel to the main body of the sheet 5.

The lower set of rotary dies, indicated generally by the numerals 42 and43, are similarly mounted and arranged, the die 42 being constructedidentically with the die 34. The lower rotary die 43 is constructedidentically with the upper rotary die 33, and they cooperate to im parta 60 angle to the sealing element 44 at the very edge of the lower sheet6.

From station No. 2, which is shown in FIG. 4, the sheets 5 and 6 areprogressed to station No. 3, at which location there is disposed anothergroup of vertically spaced sets of driven rotary dies, mounted forrotation upon the frame F and spaced transversely thereof. As shown inFIG. 5. the upper set is comprised of a pair of cooperating rotary diesidentified generally by the numerals 45 and 46. These dies consist ofelongated shafts rotatably mounted upon the frame F and carrying at eachof its ends a cooperating rotary die member constructed and arranged toimpart additional shaping to the lateral portions of the sheets 5 and 6,preparatory to forming a rectangular duct therefrom. The rotary die 45has a die member at each of its ends, which has an annular surface 47separated from an outwardly tapering surface 48 by an annular groove 49.At the larger end of this die is an essentially flat surface 50, whichextends essentially normal to the shaft upon which these die members aremounted, and a reduced annular surface 51 is provided outwardly thereof.

The die 46 carries at each of its ends a cooperative rotary die membercharacterized by an annular surface 52 separated from an outwardlydiminishing frustoconical surface 53 by an annular rib 54, which ispositioned to extend into the groove 49 as the die members rotate. Thisdie member is further characterized by a surface 55 which extendsessentially normal to the shaft of the die 46 and is positioned slightlyoutwardly of the surface so as to cooperate therewith to impart a 90angle to the seam element 56. It is further characterized by an enlargedannular surface 57, which cooperates with the cylindrical surface 51 tocause the lip 41 to extend essentially normally to the sealing element56.

The lower set of rotary dies, identified by the numerals 58 and 59, aresimilarly constructed and arranged to shape the lower sheet 6. Therotary die 58 is constructed identically with the rotary die 46, and therotary die 59 is constructed identically to the rotary die 45, and theycooperate in a similar manner to impart the same shape to the lateralportions of the sheet 6, except, of course, that the extreme edgeportion, or sealing element 44, carries no lip element corresponding tothe lip element 41 because of its narrower width.

From station No. 3, which is shown in FIG. 5, the sheets move to stationNo. 4 at which they encounter the structure shown in FIG. 6. At stationNo. 4, the sheets reach a helper station at which they are guidedinwardly by a plurality of rotatably mounted rollers 60, each of whichis carried by a spindle or shaft 61 and is supported upon one oftransverse members 62 or 63 as shown in FIG. 6. It is at this stationthat the sheets 5 and 6 first encounter the fixed die member 10, whichare positioned so as to be disposed just inwardly of the break lines 64,which were imparted to the two sheets by the cooperative action of theannular ribs 54 and grooves 49 of station No. 3, as shown in FIG. 5. Itwill be noted that the rollers 60 are positioned so as to engage thelateral portions of the sheets 5 and 6 just inwardly of the sealingelement. These rollers 60 are not driven, but are free to rotate on theshaft 61, which in turn are adjustably mounted on the transverse members62 and 63 through the use of sleeves as shown. These rollers 60 guidethe lateral portions of the sheets 5 and 6 inwardly toward each other soas to progressively break the sheets at the break line 64 and guide theminto the rotary dies at station No. 5, which are shown in FIG. 7.

FIG. 7 shows a plurality of driven rotary dies cooperating with thefixed dies 10. A power driven upper shaft 65 is rotatably mounted uponthe frame F to extend transversely thereof and carries at each of itsend portions a rotary die member 66 having a cylindrical surface 67 anda 53 outwardly bevelled surface 68. Each of these rotary die members 66are positioned so that the cylindrical surface 67 bears upon the uppersheet 5 just inwardly of outer surface of the fixed die member 10 andthe bevelled surface is disposed just outwardly thereof so as to bringthe lateral portions of the sheet member 5 inwardly 53 from the plane ofthe sheet. The shaft 65 also carries at each end a disk-shaped guidingmember 69, which rotates with the shaft and extends into the angleformed by the sealing element 56 so as to guide the outermore lateralportions of the sheet inwardly toward the sheet 6, as shown in FIG. 7.

A lower and similarly mounted shaft 70 carried identically constructedguide members 69 and a pair of rotary die members 71, which areconstructed and positioned similar to the rotary die member 66, exceptthat the angle of the bevel 72 is such as to impart a 57 angle to thelateral portions of the sheet 6 and thus move the sealing element 44inwardly at each side to an extent farther and ahead of the sealingelement 56 of the sheet 5. This arrangement is utilized in order toinsure that upon further movement of the lateral portions of the twosheets inwardly the sealing elements will mate properly.

From station No. S, as shown in FIG. 7, the sheets 5 and 6 move onwardlyto station No. 6, which is shown in FIG. 8. Here again, the sheetsencounter a helper station in the form of rollers 73, each of which isrotatably mounted for free rotation about a spindle 74 that is carriedby a sleeve 75 upon a transverse member such as 76 or 77. These rollers73 guide the lateral portions of the sheets 5 and 6 further inwardly asthey bend further at the break lines 64. It will be noted that therollers 73, which are carried by the lower transverse member 77, arepositioned inwardly slightly farther than those carried by the uppermember 76 so that the sealing elemeat 44 is disposed somewhat inwardlyof the sealing element 56 and the lip 41 at each side of the machine.Note that the two sheets 5 and 6 have been gradually and progressivelyformed in sequential steps into two oppositely facing channel memberswhich are essentialiy U-shaped in cross-sectional configuration. Asthese sheets continue to progress through the machine, even furtherbending takes place until a truly rectangular configuration is obtained.The effect of the rollers 73 is felt by the material of the sheets 5 and6 which is disposed thercahead so that the sheets are properly guidedinto the mechanism at station No. 7, which is shown in FIG. 9.

At station No. 7 there is provided a plurality of rotary die membersconstructed and arranged to close the rectangular configuration andcommence to close the lip 41 around the sealing elements 44 so as tohold the latter between it and the scaling element 56. Carried by theframe F at opposite sides of the fixed dies 10 and cooperating therewithis a pair of rotary die members which are identical in construction andidentified generally by the numeral 78. Each of these rotary die members78 has a cylindrical compressing surface 79 and a slightly bevelledinner end surface 80. The latter gradually bends the lateral portions ofthe sheet 5 inwardly to a angle against the fixed die and at the sametime the cylindrical surface 79 brings the sealing element 56 and thelip 41 downwardly and around the relatively inwardly disposed sealingelement 44. A pair of rotary die members indicated generally by thenumeral 81 is also carried by the frame F in position to cooperate withthe rollers 78 and toward that end they are constructed to provide abevelled camming surface 82, which engages the lip 41 and brings itinwardly to an angulated position relative to the sealing element 56 andsomewhat around and below the sealing element 44 of the sheet 6. Thusthe construction shown completes the 90 bend at the side of the duct andcommences the closing of the seam member which ultimately consists ofthe two sealing elements 44 and 56 held in sealed position by thesealing element 41, as will be hereinafter described. It will be notedthat the two rotary die members 81 are positioned at opposite sides ofthe fixed die members 10 and have similar bevelled inner ends whichcomplete the 90 bend of the sheet 6 at the break line 64 in addition tocommencing the closing of the seam.

From position 7 as shown in FIG. 9, the sheets and 6 move to station No.8, at which they encounter the structure shown in FIG. 10. At thisstation there is provided at each of the sides of the now rectangularconfiguration additional camming structure constructed and arranged tocomplete the formation of the seam. As shown in FIG. 10, mounted uponthe frame F outwardly of the fixed dies 5, and in position to receivetherein the seam elements 44 and 56 and the lip 41, is a pair of cammingmembers 83 and 84. These camming members 83 and 84 are fixed andvertically spaced from each other a distance essentially equal to thecombined thickness of the elements 41, 44 and 56. The end portions ofthe camming members 83 and 84 which face toward the direction from whichthe sheets 5 and 6 move are somewhat flared as shown in the detailedview of FIG. 14 to facilitate entrance of these elements thereinto. Asthe sheets 5 and 6 are drawn past station No. 8, the seam which is nowcomprised of the seam elements 44 and 56 and the lip 41 is completed,the lip 41 being brought into flattened position around and below thesealing element 44 of the lower sheet 6. Elements 83 and 84 are providedat each side of the duct so that as the sheets pass thereby the seam iscompleted to the configuration shown in FIG. 10.

As the now rectangular configuration comprised of the sheets 5 and 6leave station No. 8 as shown in FIG. 10, it proceeds to station No. 9,which is shown in FIG. 11. At this station the seam at each side of theduct, which consists of the elements 41, 44 and S6 in flattenedcondition, passes through one of a pair of vertically spaced rotary diemembers 85 and 86, one each of which is disposed at each side of theduct. Each of the rotary die members 85 is characterized by acylindrical surface 87, which bears against the outer surface of thesealing element 56 and a pair of recesses 88 which are oppositelydisposed within said cylindrical surface. A bevelled end surface 89 isalso provided to facilitate movement of the rectangular duct thereby.Each of the rotary die members 86 is characterized by a cylindricalsurface 90 which bears against the underside of the sealing lip 41 andcompresses the latter to flatten the seam and compress it. Each rotarydie member has a pair of outwardly extending buttons 91 which arepositioned so as to pass directly opposite the recesses 88 as theyrotate, and thus impart a locking button 92 at spaced locationsapproximately 3 inches apart along the seam to the metal of the elements41, 44 and 56, which make up the seam. This button 92 positively locksthe elements which make up the seam to each other and precludesseparation during subsequent handling of the duct. An enlarged detailedview of the button being formed is shown in FIG. 16.

FIG. 12 shows a diagrammatic perspective view which illustrates themanner in which the individual sheets of the roll 4 gradually movetherefrom through the machine and assume in sequential steps the shapewhich is illustrated at the locations identified thereon by numeralscorresponding to the stations hereinbefore described. Thus it can beseen that the two flat sheets of metal 5 and 6 are progressivelyconverted from flat sheets into a duct having a rectangularcross-sectional configuration as these sheets are drawn through themachine, the duct entering the machine at one end in the form of twosheets and being discharged from the opposite end in the form of acontinuous rectangular duct which can be constructed of any desiredpredetermined length merely by providing a roll having two such sheets 5and 6 of such desired length.

The feeding and initial crimping mechanism shown in FIG. 3 andidentified by the letter C is controlled through a handle member 93which is fixedly connected to rotate with a transverse shaft 94 which isrotatably mounted and extends through the frame F. At each end of theshaft 94 there is a cam member 95, the details of which are shown inFIG. 13. These cams 95 are fixed to the shaft 94 and rotate therewith,and they have an irregular camming surface designed to control therelative movement of the members 17 and 28 toward and away from therotary die members 18 and 29. This is accomplished through the use ofrollers or cam followers 96, which are carried at each end of themembers 17 and 28. Reference to FIG. 13 will disclose the irregularcamming surface of the cams 95.

The lever 93 and cam 95 are positioned in FIG. 1 so as to present thecamming surfaces having the maximum radius to the cam followers 96. Thisposition is identified as position No. 1 and, since the camming surfaces97 and 98 having the largest radius engage the cam followers 96 in thisposition, the upper roll 17 and the lower roll 28 will be positioned inopen position and in nonengaging relation to the rolls 18 and 29. Whilein this position the forward end of the lower sheet of metal 6 isinserted between the rolls 28 and 29 and the lever member 93 and thecams 95 are rotated about the shaft 94 to position No. 2, which is atthe camming surfaces identified by the numerals 99 and 100. It will benoted that the distance from the center of shaft 94 to the cammingsurface 99 is essentially equal to the distance between that shaft andthe camming surface 97 at position No. 1 and hence the upper roll 17will remain in open position. On the other hand, the distance from thecenter of shaft 94 to the camming surface 100 is substantially less thanthat between that shaft and the camming surface 98 at position No. 1 andhence the roll 28 will be moved by the springs 20 into engagement of theforward end of the lower sheet 6 to grip the same in cooperation withthe roll 29.

One the sheet 6 has been gripped between the rolls 28 and 29, the lever93 and cams 95 may be rotated further until the camming surfacesidentified by the numerals 101, 102 bear against the cam followers 96.This is known as the rest position in which the rolls 28 and 29 areclosed and the rolls 17 and 18 are also closed. This is true because itwill be seen that the distance from shaft 94 to camming surface 102 hasbeen reduced sufficiently so that roll 17 is permitted to lower and gripthe forward end of the upper sheet which is extended therebetweenmanually just prior to movement of the lever to rest position, orposition No. 3. Further movement of the lever 93 sufficient to cause thecamming surfaces identified by the numerals 103 and 104 to engage thecam followers 96 (position No. 4) leaves the rolls 17 and 18 and 28 and29 in position holding the sheets 5 and 6 in the same manner as inposition No. 3, but also closes an electrical switch which causes thedriving motor of the machine to be activated and rotate the rolls 17,18. 28 and 29 to cause the sheets 5 and 6 to be progressed through themachine.

In the event a flattened seam is desired, the frame F may be constructedof sufficient length to also carry the mechanisms shown in FIGS. 30-32,which will be described hereinafter. Description of the structure willbe made hereinafter subsequent to the description of the structuresshown in FIGS. 17-29 inclusive.

FIGS. 17-29 illustrate a similar machine to that shown in FIGS. 1-16,except that the dies are constructed and arranged to form the seams atthe corners of the rectangular duct rather than at the intermediateportions of the sides of the duct. The same cradles may be utilized asdesired, but the roll of metal will be comprised of sheets of differentwidths as is shown in FIGS. 17-28.

The same type of feeding and initial crimping mechanism may be utilizedexcept that the rolls will be constructed differently. Thus in FIG. 17,station No. 1 is shown wherein the vertically movable roll 110 issubstantially shorter so as to conform to the narrower widths of theupper metal sheet 111. The roll 110 is provided with a resilientintermediate portion and metal end portions comparable to theconstruction of the roll 17. The cooperating roll 112 is constructedsimilarly to the roll 18, except that it. too, is shorter to conform tothe narrower width of the upper sheet 111. The lowest roll 113 isconstructed similarly to roll 28, but it is longer in length to conformto the substantially greater width of the lower sheet 114. The upper ofthe lower set of rolls 115 is constructed in the same manner as roll 29,except that it, too, has a substantially greater length to conform tothe greater width of lower sheet 114. The rolls 110, 112, 113, and 115form the same functions of gripping and moving the sheets forwardly asdo the rolls shown in FIG. 3. The rolls 113 and 115 form a angle of theedge portion of the sheet 114 in the same manner as the rolls 28 and 29function. Since the rolls 110 and 112, however, do not have a bevelledend portion 22, the only effect these rolls have upon the upper sheet111 is to impart the transverse and longitudinal ribs to the sheets toprovide added rigidity in the same manner that the beads 26 and ribs 27function upon the sheet 5.

FIG. 18 shows station No. 2 of the modified form of the invention. Asthe sheets pass through station No. 1, as shown in FIG. 17, they enterthe structure shown in FIG. 18 for further modification corresponding tothat which takes place in station No. 2 of the preferred embodiment.Thus, the rolls 116 and 117 correspond to rolls 42 and 43, and similarlyimpart a 60 angulation to the seal element 118 at each of the lateraledges of the sheet 114. The sheet 111 enters a. pair of guiding channels119 and 120 which are supported by the frame F and extend longitudinallythereof at the central position shown. No modification of sheet 111takes place at station No. 2, and the only modification to sheet 114 isto impart a 60 angulation to the sealing element 118 and progress thesheet forwardly to station No. 3, which is shown in P16. 19.

At station No. 3, the upper sheet 111 continues to ride within thechannel members 119 and 120, and no modification thereof is accomplishedat this station. The frame E carries at this station, however, a pair oftransverse shafts 121 and 122 which are power-driven and carrycooperative rotary die members. At each end of the shaft 121 there is arotary die having a cylindrical surface 123 which is reduced to abevelled surface 124 and tapers gradually thereto as at 125. Each ofthese rotary die members cooperate with another rotary die member suchas 126 that is carried by the lower shaft 122. The rotary dies 126 havea somewhat bevelled end surface 127 which cooperates with the bevelledsurface 125 to move the sealing element 118 to extend normal to theimmediately adjacent lateral portion of the sheet 114. The surfaces 124and 128 cooperate to hold the material immediately adjacent the sealingelement 118 firmly.

Disposed inwardly of the rotary dies carried at the ends of shafts 121and 122 are two pairs of cooperating dies which provide the initialbreak to the sheet 114 at break lines 129 and 130 which eventuallybecome the corners of the duct. The shaft 121 carries a pair ofidentical rotary dies 131, each of which is characterized by an annularcentrally disposed rib 132, and the adjacent surfaces of which slopeaway therefrom to a diminished radius, as clearly shown in FIG. 19.Cooperating with each of these dies 131 and carried by the shaft 122 inposition to form the break lines 129 and 130 is a pair of rotary diesindicated by the numeral 133. Each of these dies is characterized by anannular groove 134, whi h is centrally located intermediate the ends ofthe die and by an adjacent tapering surface which increases in radiusfrom the groove toward the outer end of the shaft and is indicated bythe numeral 135. As shown, these rotary dies cooperate to provide theinitial shaping of the sheet 114 toward a U-shaped construction adaptedto be closed eventually by the sheet 111.

As the sheets 111 and 114 leave station No. 3, they proceed towardstation No. 4, which is shown in FIG. 20. Here again the upper sheet 111continues to be carried by the channel members 119 and withoutmodification thereto. It will be noted, however, that the fixed diemembers 10 are now disposed above the lower sheet 114 just inwardly ofthe break lines 129 and 130. At this station there is provided atransverse shaft 136 which rotatably mounts by means of sleeves 137 andspindles 138, a pair of guiding rollers 139 which rotary freely on thespindles. These rollers 139 provide a function comparable to thatprovided by the rollers 60 in station No. 4 of the first embodiment and,as will be seen by reference to FIG. 20, bring the lateral portion ofthe sheet 114 upwardly and inwardly and guide the same into the dies atstation No. 5, which is shown in FIG. 21.

At station No. 5 in FIG. 21, the upper sheet 111 is still carried in thechannel members 119 and 120 and remains unmodified. The frame F carriesa transverse shaft 140 which rotatably mounts a pair of rotary dies suchas indicated by the numeral 141. Each of these dies has an annularsurface 142 and an outwardly bevelled surface 143 and is positioned sothat the latter surface engages the lateral portions of the sheet 114and bends them upwardly approximately 57 off the plane of the sheet 114.It will be noted that each is positioned so that the annular surface 142is disposed immediately below the fixed die members 10 and the bevelledsurfaces 143 commence at the outer surface of these fixed die members.Also carried by the driven shaft 140 and disposed outwardly of therotary dies 141 is a pair of guiding disks or rollers indicatedgenerally by the numeral 144. These guiding rollers are bevelled to cometo an edge intermediate their axial ends and are shaped so as to engageand complement the edge portion of the sheet 114, the edge 145 of eachof these rollers extending into the angle formed by the sealing element118.

As the sheets leave station No. 5 which is shown in FIG. 21, they moveto station No. 6 which is shown in FIG. 22. At this station the uppersheet 111 still remains unmodified and is carried by the channel members119 and 120. A transversely extending shaft 146 is carried by the frameF and mounts by means of a sleeve 147 and a spindle 148, a freelyrotatable roller 149 at each of the outer sides of the fixed die 10. Thespindles 148 extend upwardly and slightly outwardly and position therollers 149 so as to bring the lateral portions of the sheet 114inwardly toward the fixed die members 110. These guide rollers 149 bringthe lateral portions to extent approximately 75 from the plane of thesheet 114 and guide the sheet into the mechanism of station No. 7, whichis shown in FIG. 23.

The channel members 119 and 120 terminate between stations No. 6 and No.7 and at station No. 7 sheet 111 is acted upon by a pair of rotary diesindicated generally by the numeral 150. This pair of rotary dies 150 ismounted upon a powered transverse shaft 151, which is carried by theframe F. Each of the rotary die members 150 cooperates with anotherrotary die member indicated generally by the numeral 152, which ispositioned immediately therebelow and supported upon a shaft 153 whichlikewise is powered and supported by the frame F. Each of the rotarydies 150 has an annular die surface 154 which terminates just short ofthe lateral edge of the sheet 111 and merges with an outwardly flaringdie Surface 155, as shown in FIG. 23. The lower dies 152 have an annularsurface 156 which cooperates with the annular surface 154 and mergesinto a diminishing die surface 157 which cooperates with the flaring diesurface to form the outer edge portion of the sheet 111 into anangulated lip 158. It will be noted that the break lines 129 and 130 arespaced a distance less than the width of the sheet 111 so that the lip158 is formed opposite the outer end of the sealing element 118 andextends downwardly thereby. It will also be noted that the inner ends ofthe rotary dies 152 are bevelled as at 159 to facilitate engagement andpassage of the lateral portions of the sheet 114 as the sheet movesthrough the machine. The rotary dies 152 function to move the lateralportion of the sheet 114 so that they extend normal to the centralportion of the sheet and are brought flush against the outer surface ofthe inner dies to complete the rectangular configuration. They alsofunction to bring the sealing element 118 inwardly so that it will bepositioned inwardly of the lip 158.

As the two sheets 111 and 114 move from station No. 7, as shown in FIG.23, they proceed to station No. 8, which is shown in FIG. 24. It is atthis station that the sealing lip 158 is brought to vertically extendingposition and normal to the sealing element 118. This is accomplishedthrough the use of a pair of rotary die members indicated generally bythe numeral 160, which are carried upon a transverse shaft 161 mountedfor rotation upon the frame F. This shaft 161 is powered to rotate thetwo dies 160 at their position directly above the sealing element 118and lip 158. Each of the dies 160 has an annular surface 162 and anadjacent radially extending surface 163 which extends outwardlytherefrom at a posittion just outwardly of the break at the inner end ofthe lip 158. It also has an adjacent bevelled surface 164 which guidesand cams the lip 158 into position where the surface 163 can force asharp break or bend at the base of the lip. Cooperating with each of therotary dies 160 is one of a second pair of rotary dies indicatedgenerally by the numeral 165. Each of these dies is carried upon a shaft166 which in turn is mounted upon the frame F and is likewisepower-driven as shown. Each of the dies 165 has an annular die surface167 which merges with a bevelled surface 168 that extends inwardlytherefrom and is adjacent to a radially extending die surface 169. Thesurface 169 engages the inner surface of the lip 158 and the annularsurface 167 cooperates with the annular surface 162 while the bevelledsurface 168 guides the lateral portions of the sheet 114 inwardly. It isat this station that the sealing lip is brought to a 90 orientation andthe sealing element 118 is brought snugly up against the undersurface ofthe sheet 111 immediately adjacent this lip preparatory to forming aseam therewith.

As the rectangular configuration shown in FIG. 24 leaves station No. 8,it moves toward station No. 9 which is shown in FIG. 25. It is at thisstation that the lip 158 is brought inwardly to a partially sealingposition. This is accomplished by a pair of rotary dies indicatedgenerally by the numeral 170 and carried by a powerdriven shaft 171which is rotatably mounted on the frame F. The two rotary dies 170 arepositioned just outwardly of the two fixed die members 10 and arecharacterized by an annular surface 172 which bears against the uppersurface of the sheet 111 and cooperates with one of a pair of rotarydies indicated generally by the numeral 173. These rotary dies 173 arepositioned immediately below one of the dies 170 and are characterizedby a frusto-conical camming surface 174 which terminates with a radiallyextending surface 175. These dies are mounted upon a shaft 176 whichlikewise is mounted upon the frame F. As these dies engage the lip 158,the end of the lip bears against the radial die surface 175 of the die173, and the outer surface of the lip 158 is cammed inwardly by thefrusto-conical camming surface 175 in cooperation with the annularsurface 172 of the die 170. The inner end of the die 173 bears againstthe outer surface of the lateral portions of the sheet 114 which has nowbecome the side walls of the rectangular duct.

As the sheets leave station No. 9 which is shown in FIG. 25, they movetoward station No. 10, which is shown in FIG. 26. At station No. 10 theedge portions of the sheet 111 pass between a pair of camming members177 and 178 at each side of the rectangular duct. These camming membersare flared similarly to those shown in FIG. 15 and each pair issupported upon the frame F by brackets such as indicated by the numeral179. The camming members 177 and 178 compress the lip 158 around andupwardly against the underside of the sealing element 118 and cam theseelements tightly against the underside of the portion of the sheet 111which extends laterally beyond the side walls of the duct. This actionis highly similar to that described with respect to the preferredembodiment as is accomplished by the structure shown in FIG. 15.

As the duct leaves station No. 10 as shown in FIG. 26, it moves to thefinishing station shown in FIG. 27. At this finishing station there isprovided a transverse shaft 180 which is mounted upon the frame F forrotation and is powered. It carries a pair of rotary die membersindicated generally by the numeral 181 each of which is characterized byan annular surface 182 which has a pair of recesses 183 formed in itsouter surface. These rotary dies 181 cooperate with a pair of rotarydies mounted immediately therebelow and identified generally by thenumeral 184. These dies likewise have an annular surface 185 whichcooperate with the annular surface 182 to further compress the seamformed by the elements 118 and 158 and further carry a pair ofoppositely disposed outwardly extending nipples 186 which are adapted toextend into the recesses 183 and form a button in the elements 118, 158,and the portion of the sheet 111 that extends outwardly beyond the sidewalls of the duct. In this manner, each of these elements is positivelylocked to the other to prevent separation during handling of the duct.The construction of the button is similar to that shown in FIG. 16.

The detailed view of FIG. 28 merely shows the manner in which the sheet111 rides upon the channels 119 and 120 as hereinbefore described.

FIGS. 30-32 are shown herein to disclose the manner in which the seam ofthe first embodiment may be fiattened, if such is desired. It will bereadily appreciated that if it is desired to flatten the seam of thesecond embodiment, it may be accomplished in the same manner by merelymoving the rotary die elements upwardly in position to engage the seamsat the corners and cam them downwardly. As shown, the seam can beflattened by adding a station 10 immediately forwardly of station No. 9of the first embodiment, the mechanism being comprised of two pairs ofcooperating rotary dies mounted upon the frame F in position to engagethe seam, the upper two dies identified by the numeral 187 beingprovided with a frusto-conical die surface 188 which flares outwardlyand cooperates with a lower die indicated generally by the numeral 189which carries a frusto-conical cooperating die surface 190. Thecooperating surfaces 188 and 190 provide an initial bend to the seam sothat it extends downwardly at approximately a 45 angle.

From station No. 10 as shown in FIG. 30 the duct moves to station No. 11as shown in FIG. 31 wherein the seam at each side of the duct engages aflattening die that is mounted for rotation on the frame F. Theseflattening dies 191 are characterized by a flat end surface 192 and anadjacent bevelled surface 193 which together cooperate to engage andflatten the seam against the extension of the fixed inner die 10 asshown. The dies 188 and 190 and 191 can each be driven by a geararrangement such as is shown in FIG. 32 which may be incorporated in thedrive mechanism disclosed in FIG. 2.

FIG. 2 shows diagrammatically the gear train provided to drive thevarious rotary dies hereinbefore described so as to cause the metalsheets to be progressed through the various sequential stepshereinbefore described. A source of power (not shown) such as anelectric motor is connected in driving relation to a drive gear 195.This drive gear 195 is connected in driving relation to a second drivegear 196 which is rotatably mounted upon the frame F. A drive chain 197extends around the drive gear 196 in the manner shown to drive theinter-engaging assembly of gears at the front and rear end of the frameF. The loca tion of the various stations has been indicated in FIG. 2 byidentifying the various driving gears with the numerals of the shafts orrotary die members which they drive. It is believed that theinterrelation of these gears and the operation of the driving train willbe readily appreciated by anyone familiar with chain drives.

From the above it can be readily seen that we have provided a novelmachine which utilizes a plurality of rotary dies in such a manner thata pair of fiat metal sheets may be fed into one end of the machine and acompletely constructed rectangular duct can be taken from the oppositeend as a result of an entirely automatic operation. Since the machine ismovable, it can be readily taken to any location where it is desired toutilize same, and, in fact, can be positioned adjacent an assembly linein a mobile home manufacturing plant, for example, so as to produce anddischarge rectangular ducts of any desired length and feed them directlyinto the partially constructed home as they pass our machine in theproduction line. A rectangular duct of any length desired can beproduced without difficulty and at a very substantial saving in cost,time and material. Moreover, there are no length limitations, and allthat is required to produce a duct of a prescribed length is to providea preparpared roll of a pair of sheets of that length and feed them intothe machine.

It will, of course, be understood that various changes may be made inthe form, details, arrangement and proportions of the parts withoutdeparting from the scope of this invention which consists of the mattershown and described herein and set forth in the appended claims.

What is claimed is:

l. A method of forming a rectangular air duct in a single continuousoperation consisting in:

a. providing a pair of elongated flat metal sheets in spaced parallelrelation,

b. progressively crimping the inner lateral portions at each side ofeach of said sheets longitudinally from one of its ends toward the otheralong a corner line to facilitate bending of the lateral portions ofeach of such sheets toward the corresponding lateral portions of theother,

e. bending simultaneously the lateral portions of such sheets towardeach other progressively in increments along their lengths until thelateral portions of one of such sheets abuts the lateral portions of theother throughout their lengths and a rectangular configuration incross-section is thereby defined, and

d. progressively forming an interlocking seam in the abutting lateralportions of such sheets from a point adjacent one of their ends towardthe other to positively lock and maintain such sheets in a cooperativerectangular duct-defining relation.

2. The method defined in claim 1, and

e. progressively bending the outer lateral portions of said sheetslongitudinally along seam lines so as to cause said outer lateralportions to extend substantially normal to their adjacent inner lateralportions and parallel to an in abutting relation to each other when therectangular configuration has been defined, and

f. progressively bending the extreme lateral portions of one of saidsheets so as to extend away from and parallel to its supporting innerlateral portions preparatory to the formation of an interlocking seamtherefrom.

3. The method defined in claim 2, and finally bending said extremelateral portions of one of said sheets so as to extend around the outeredge of the extreme lateral portion of the other sheet and along theopposite side thereof in close abutting relation preparatory to theformation of an interlocking seam therein.

4. The method defined in claim 1 wherein forming said interlocking seamconsists in simultaneously deforming in a progressive manner along theirlengths the abutting lateral portions of said sheets while they are inabutting relation.

5. The method defined in claim 1 wherein forming said interlocking seamconsists in simultaneously deforming in a progressive manner along theirlengths the abutting lateral portions of said sheets at points spacedalong substantially the entire lengths of said abutting portions tocause the deformations produced therein to lock such portions to eachother.

6. The method defined in claim 1 wherein each of the crimping andbending steps set forth therein is performed sequentially andprogressively upon such sheets from one of their ends toward and to theother end.

7. The method defined in claim 1 wherein each of said crimping. bending,and forming operations is performed sequentially and progressively uponsuch sheets from one of their ends toward and to the other end.

8. The method defined in claim 1 wherein each of the crimping operationsset forth therein is accomplished by passing said sheets longitudinallythrough cooperative rotary crimping members from one of their endstoward and to the other end.

9. The method defined in claim 1. wherein each of the bending operationsset forth therein is accomplished by passing said sheets longitudinallyfrom one of their ends toward and to the other end between cooperativerotary bending members.

10. The method defined in claim 1 wherein the seam forming operationsset forth therein are accomplished by passing said sheets longitudinallyfrom one of their ends toward and to the other end between cooperativerotary die members.

11. The method defined in claim 1 wherein the crimping and bendingoperations set forth therein are accomplished by passing such sheetslongitudinally from one of their ends toward and to the other endbetween cooperative rotary members.

12. The method defined in claim 1 wherein the crimping, bending, andforming operations set forth therein are accomplished by passing suchsheets longitudinally from one of their ends toward and to the other endbetween cooperative rotary members.

13. A method of forming a duct having a rectangular cross section in asingle continuous operation consisting a. providing a pair of elongatedfiat metal sheets in spaced parallel relation,

b. progressively crimping a sharp corner line in the inner lateralportion of each of said sheets at each of its sides,

c. progressively bending the lateral portions of each of said sheets atits corner lines toward each other in increments along their lengthsuntil the lateral portions of one of said sheets extend adjacent to andalong the lateral portions of the other throughout their lengths andsaid sheets thereby cooperatively define a rectangular configuration incross section, and

d. progressively securing such adjacent lateral portions of the one suchsheet to those of the other along the length of said sheets in order tomaintain said sheets in cooperative rectangular duet-defining relation.

14. A method of forming a rectangular air duct in a single continuousoperation consisting in:

a. providing a. pair of elongated flat metal sheets in spaced parallelrelation,

b. progressively crimping the inner lateral portions of said sheetslongitudinally from one of their ends to the other along corner lines tofacilitate bending of the lateral portions of such sheets toward eachother,

c. simultaneously bending the lateral portions of such sheets towardeach other progressively in increments along their lengths until thelateral portions of one of such sheets overlaps the lateral portions ofthe other throughout their lengths and a rectangular configuration incross section is thereby defined, and

d. progressively forming an interlocking seam in the overlapping lateralportions of such sheets from one of their ends to the other topositively lock and maintain such sheets in a cooperative rectangularductdefining relation.

15. The method defined in claim 14, and

e. progressively bending the outer lateral portions of said sheetslongitudinally along seam lines so as to cause said outer lateralportions to extend substantially normal to their adjacent inner lateralportions and parallel to and in abutting relation to each other when therectangular configuration has been defined, and a f. progressivelybending the extreme lateral portions of one of said sheets so as toextend away from and parallel to its supporting inner lateral portionsprior to the formation of an interlocking seal therefrom.

16. The method defined in claim 15, and finally bending said extremelateral portions of one of said sheets so as to extend around the outeredge of the extreme lateral portion of the other sheet and along theopposite side thereof in close abutting relation prior to the formationof an interlocking seam therein.

17. The method defined in claim 14 wherein forming said interlockingseam consists in simultaneously deforming in a progressive manner alongtheir lengths the over lapping lateral portions of said sheets whilethey are in abutting relation.

18. The method defined in claim 14 wherein forming said interlockingseam consists in simultaneously deforming in a progressive manner alongtheir lengths the overlapping lateral portions of said sheets at pointsspaced along substantially the entire lengths of said overlappingportions to cause the deformations produced therein to lock suchportions to each other.

19. Method of forming a rectangular-duct in a single continuousoperation consisting in a. providing a pair of elongated flat metalsheets in spaced parallel relation,

b. progressively moving longitudinally the latteral portions of eachsaid sheets at each of its sides through a rotary crimping die to form apair of spaced sharp corner lines therein extending substantiallythroughout the length of said sheet,

0. progressively moving the lateral portions of said sheets against andpast a series of bending rollers and thereby progressively bending suchlateral portions toward each other until the lateral portions of one ofsaid sheets abuts the corresponding lateral portions of the otherthroughout the length of said sheets to cooperatively define arectangular configuration in cross section, and

d. progressively securing such adjacent lateral portions of the one suchsheet to those of the other along the length of said sheets to maintainsuch sheets in cooperative rectangular-duct defining relation.

20. The method defined in claim 1 wherein said bending operationincludes the step of progressively camming the lateral portions of suchsheets toward each other in increments along their lengths.

21. The method defined in claim 1 wherein said bending operationincludes camming the lateral portions of such sheets toward each otherprogressively in increments along their lengths until the lateralportions of one of such sheets abuts the lateral portions of the otherthroughout their lengths and a rectangular configuration in crosssectionis thereby defined.

22. The method defined in claim 1 wherein said bending operationincludes camming the lateral portions of such sheets toward each otherprogressively in increments along their lengths, and

e. progressively bending the outer lateral portions of said sheetslongitudinally along seam lines so as to cause said outer lateralportions to extend substantially normal to their adjacent inner lateralportions and parallel to and in abutting relation in part at least toeach other when the rectangular configuration has been defined.

23. A method of forming a rectangular air duct in a single continuousoperation consisting in:

(a) providing a pair of elongated flat metal sheets in spaced parallelrelation,

(b) progressively crimping the inner lateral portions at each side of atleast one of such sheets longitudinally from a point adjacent one of itsends toward the other along a corner line to facilitate bending of thelateral portions of such crimped sheet toward the corresponding lateralportions of the other sheet,

(0) bending the lateral portions of such crimped sheet toward thelateral portions of the other sheet progressively in increments alongits length until the lateral portions of each of such sheets overlapsthe lateral portions of the other of such sheets along their lengths anda rectangular configuration in crosssection is thereby defined, and

(d) progressively forming an interlocking scam in the overlappinglateral portions of such sheets from a point adjacent one of their endstoward the other to positively lock and maintain such sheets in acooperative rectangular duct-defining relation.

24. The method defined in claim 23 and bending the extreme lateralportions of one of such sheets so as to extend around the outer edge ofthe extreme lateral portion of the other of such sheets and along theopposite side thereof in close overlapping relation preparatory to theformation of an interlocking seam therein.

25. The method defined in claim 23 wherein forming said interlockingseam includes simultaneously deforming in a progressive manner alongtheir lengths the overlapping lateral portions of each of said sheetswhile they are in overlapping relation.

26. The method defined in claim 23 wherein each of the crimping andbending steps set forth therein is performed sequentially andprogressively upon such crimped sheet from one of its ends toward and tothe other end.

27. The method defined in clam 23 wherein each of said crimping,bending, and forming operations is performed sequentially andprogressively upon such crimped sheet from one of its ends toward and tothe other end.

28. The method defined in claim 23 wherein said bending operationincludes the step of progressively comming the lateral portions of suchcrimped sheet toward the corresponding lateral portions of the othersuch sheet in increments along their length.

29. The method defined in claim 23 wherein the bending operations setforth therein is accomplished by passing such crimped sheetlongitudinally from one of its ends toward and to the other end betweenopposed camming members which bend the lateral portions of such crimpedsheet toward the lateral portions of the other sheet.

30. The method defined in claim 23 wherein said seam forming operationincludes simultaneously deforming in a progressive manner along theirlengths the overlapping lateral portions of said sheets in such a manneras to cause local areas of the overlapping portion of one of such sheetsto extend into the plane of the adjacent overlap ping portion of theother of such sheets.

31. The method defined in claim 23 wherein said progressive bendingoperations are conducted simultaneously at opposite sides of suchcrimped sheet in substantially equal increments.

32. The method defined in claim 23 wherein said pr0 gressive seamforming operations are conducted simultaneously and oppositely atopposite sides of such sheets.

20 3 The method defined iiiclaitn 23 wherein said propoint adjacent oneof their ends toward the other gressive crimping, bending, andseam-forming operations to positively loclc and maintain such sheets ina are conducted simultaneously along both sides of such I cooperativerectangular duct-defining relation. crirnped sheet. l l H 314 14 methodof forming a rectangular air duct in a 5 References Cited e c guo P(consisting in: The following references, cited by the Examiner, are e qd l of elongated fl metal sheets m of record in the patentedlfile of.this patent or the original spaced parallel relation, patent;

"fb) progressively crimping the inner lateral portions UNITED "STATESPATENTS a at each side of one of such sheets longitudinally from 10 1 apoint adjacent one of its ends toward the other ,2 1/1893 h 72552 alonga corner line to facilitate bending of the lateral 3/1950 Kmkead 228 '1sportions of such crimped sheet toward the c orre- 2'682850 7/1954 Close72-61 sponding lateral portions of the other sheet, 3252077 5/1966 T11354 (a) bending the lateral portions of such crimped sheet 15 7/1969 f14 toward the correspondng lateral portions of the other 3'40764010/1968 'P 72' 181 sheet progressively in increments along its length3'5o5719 4/1970 OvManey 29 200 B until the lateral portions of each ofsuch sheets over- FOREIGN PATENTS laps the lateral portions of the otherof such sheets 723,908 2/1955 Great Britain 72 52 along their lengths,and 20 385,642 11/1923 Germany 113-54 (d) progressively forming aninterlocking seam in the overlapping lateral portions of such sheetsfrom a RICHARD J. HERBST, Primary Examiner

